sl_find
char *sl_find(StringList *, const char *);
if (sl_find(charmaps, cs) == NULL)
if (sl_find(charmaps, "US-ASCII") == NULL)
if (sl_find(locales, "POSIX") == NULL)
if (sl_find(locales, "C") == NULL)
if (!sl_find(lang_list, tmp))